Answer:
The original concentration of the HCl is: 0.01925 M
Explanation:
Equation:
HCl+NaOH-------> NaCl+H₂O
Volume of NaOH added = 0.05 M
No of moles of NaOH = 15.4 mL [tex]x\frac{1 L}{1000 mL} x\frac{0.05 mol NaOH}{L}[/tex]
= 0.00077 mol NaOH
Then,
Volume of HCl solution = 40 mL x 1/1000 mL
= 0.0400 L
Therefore,
Concentration of HCl = 0.00077 mol/0.0400 L
= 0.01925 M
Now, to find the pH:
pH = -log₁₀[H⁺]
= -log₁₀(2x10⁻⁶)
= 5.7
do seeds need energy to germinate
Answer:
Seeds need oxygen so that they can produce energy for germination and growth. The embryo gets energy by breaking down its food stores. Like all organisms, this is done through a process known as aerobic respiration. —a series of reactions where energy is released from glucose, using oxygen.
If the net force acting on an object is 0 N, the forces are
Since the forces equal to 0, it's balanced because the object isn't moving.
A hutch weighs 150 lbs and it’s base has a length and width of 15 in and 34 in, respectively. What is the pressure exerted by the hutch on the floor?
Answer:0.29
Explanation:
To determine the pressure of the hutch on the floor, we must first calculate the area of the base of the hutch.
A=lw=(15in.)(34in.)=510in.2
We can now use the formula to calculate pressure.
P=FAP=150lbs510in.2P≈0.294lbin.2
Rounding to two significant figures, the pressure exerted by the hutch on the floor is 0.29lbin.2.
Which statement describes how phase changes can be diagrammed as a substance is heated?
The phase is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the phase is on the x-axis.
The time is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the time is on the x-axis.
Answer:
The temperature is on the y-axis and the time is on the x-axis.
Explanation:
Which statement describes how phase changes can be diagrammed as a substance is heated? (D is the answer)
The phase is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the phase is on the x-axis.
The time is on the y-axis and the temperature is on the x-axis.
The temperature is on the y-axis and the time is on the x-axis.
Which statement describes the appearance of a temperature-vs.-time graph? (C is the answer)
A horizontal line shows that the temperature increases at a constant rate over time.
A vertical line shows that the temperature decreases at a constant rate over time.
Horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases.
Horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.
Which of these lead (II) salts will dissolve to the greatest extent in water?
a. PbSO4, Ksp = 1.7x10^-8
b. PbI2, Ksp = 6.5x10^-9
c. PbCrO4, Ksp = 1.8x10^-14
d. PbS, Ksp = 2.5x10^-27
e. Pb3(AsO4)2, Ksp = 4.0x10^-36
Answer:
a. PbSO4, Ksp = 1.7x10^-8.
Explanation:
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In this case, since the solubility product indicates how likely a solid is able to ionize and consequently dissolve in water, we can infer that the larger the solubility product Ksp, the more ions are able dissolve in water; therefore the proper answer goes with the largest Ksp, which is a. PbSO4, Ksp = 1.7x10^-8 since the power goes closer to 1 than the other options.
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If 75J of heat are applied to 8.4 L of a gas at 732 mmHg and 298K, what is the final temperature, in K, of the gas? Cp for an ideal gas is 20.79 J/mol*K.
Answer:
309 K
Explanation:
Step 1: Convert the pressure to atm
We will use the conversion factor 1 atm = 760 mmHg.
732 mmHg × 1 atm/760 mmHg = 0.963 atm
Step 2: Calculate the moles (n) of the ideal gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 0.963 atm × 8.4 L/0.0821 atm.L/mol.K × 298 K
n = 0.33 mol
Step 3: Calculate the temperature change
We will use the following expression.
Q = n × Cp × ΔT
ΔT = Q/n × Cp
ΔT = 75 J/0.33 mol × 20.79 J/mol.K
ΔT = 11 K
Step 4: Calculate the final temperature
T = 298 K + 11 K = 309 K
Suppose there is a gaseous mixture of nitrogen and oxygen. If the total pressure of the mixture is 480 mmHg, and the partial pressure of nitrogen is 290 mmHg, calculate the partial pressure of oxygen in the mixture using Dalton's law.
Answer:
Partial pressure of oxygen = 190 mmHg
Explanation:
From the question;
Mixture contains only nitrogen and oxygen
Total pressure of the mixture = 480 mmHg
Partial pressure of nitrogen = 290 mmHg
Dalton's law states that the pressure of a system is as a result of the sum of the partial pressures of the individual components of the mixture. This means that in this mixture;
Pressure of mixture = Partial Pressure of Nitrogen + Partial Pressure of Oxygen
480 = 290 + Partial pressure of oxygen
Partial pressure of oxygen = 480 - 290
Partial pressure of oxygen = 190 mmHg
How does the density and distribution of your “stars” change as the balloon expands?
Answer:
The Universe is constantly expanding and as it expands the stars and objects in space move farther apart, just like the points on the balloon when air is blown into it. Density and distribution of "stars" as the balloon expands because when volume increases the density will increase.
Hope this Helps
0.1400 mole of sucrose, C12H22O11, contains ________ moles of C.
can you show me the formula and the correct format
Answer:
it has 12 carbon atoms and 22 hydrogen atoms and 11 oxygen atoms
Explanation:
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Explanation:
Which of the following statements correctly describes the function of cell parts?
A. The cell membrane determines which type of cell will develop.
B. The nucleus contains all the nutrients that the cell needs.
C. The mitochondria are the power plants of the cell.
D. The genes contain hemoglobin.
The statements correctly describes the function of cell parts is the mitochondria are the power plants of the cell. Therefore, option C is correct.
What do you mean by the mitochondria ?The cytoplasm of a cell contains tiny structures (fluid that surrounds the cell nucleus). The majority of a cell's energy is produced by mitochondria, which also have unique genetic material distinct from that present in the nucleus.
Oxidative phosphorylation, which produces ATP using the energy generated during the oxidation of the food we ingest, is the traditional function of mitochondria.
For the majority of biochemical and physiological activities, including growth, mobility, and equilibrium, ATP is used as the main energy source in turn.
Thus, option C is correct.
To learn more about the mitochondria, follow the link;
https://brainly.com/question/10688306
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A gas at -20c occupies volume 140 ml calculate temperature at which the volume of the gas becomes 65 ml pressure constant
Answer:
–156 °C
Explanation:
The following data were obtained from the question:
Initial temperature (T1) = –20 °C
Initial volume (V1) = 140 mL
Final volume (V2) = 65 mL
Final temperature (T2) =?
Pressure = constant.
Next, we shall convert –20 °C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Initial temperature (T1) = –20 °C
Initial temperature (T1) = –20 °C + 273 = 253 K.
Next, we shall determine the new temperature of the gas as follow:
Initial temperature (T1) = 253 K
Initial volume (V1) = 140 mL
Final volume (V2) = 65 mL
Final temperature (T2) =?
V1/T1 = V2/T2
140/253 = 65/T2
Cross multiply
140 × T2 = 253 × 65
140 × T2 = 16445
Divide both side by 140
T2 = 16445 /140
T2 = 117 K
Finally, we shall convert 117 K to celcius temperature. This can be obtained as follow:
T(°C) = T(K) – 273
T2 = 117 K
T2 = 117 K – 273
T2 = –156 °C
Thus, the new temperature of the gas is –156 °C
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A weather balloon with a volume of 3.40774 L
is released from Earth’s surface at sea level.
What volume will the balloon occupy at an
altitude of 20.0 km, where the air pressure is
10 kPa?
Answer in units of L.
Answer: The volume occupied at an altitude of 20.0 km is 34.5289 L
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
where,
[tex]P_1[/tex] = initial pressure of gas = 101.325 kPa ( sea level)
[tex]P_2[/tex] = final pressure of gas = 10 kPa
[tex]V_1[/tex] = initial volume of gas = 3.40774 L
[tex]V_2[/tex] = final volume of gas = ?
Now put all the given values in the above equation, we get the final pressure of gas.
[tex]101.325\times 3.40774=10\times V_2[/tex]
[tex]V_2=34.5289L[/tex]
Therefore, the volume occupied at an altitude of 20.0 km is 34.5289 L
Toluene is subjected to the action of the following reagents in the order given: (1) KMnO4,OH-, heat; then H3O (2) HNO3, H2SO4 (3) Br2, FeBr3 What is the final product of this sequence?
Answer:
See image attached
Explanation:
The reaction of toluene with alkaline potassium permanganate in the presence of heat leads to the oxidation of the -CH3 to give benzoic acid.
Reaction benzoic acid with HNO3/H2SO4 yields the nitronium ion (NO2+).
Recall that -COOH is a metal director and deactivated the ring towards electrophilic substitution hence the m-nitrobenzoic acid is formed.
Reaction with FeBr3/Br2 yields the product shown in the image attached.